Abstract

A new species of Cyphocharax is described from the rio Juma, which flows across the meridional Amazon basin and is a tributary of the rio Aripuanã in the rio Madeira fluvial system. Features distinguishing the new species from congeners include a longitudinally elongated caudal peduncle blotchextending from the vertical line through the adipose-fin terminus to the base of median caudal-fin rays, the number of scale series along the lateral line and between the lateral line and dorsal-fin origin, morphometric variation, and the patterns of pigmentation along the body. The species was discovered in a lesser-explored region and appears to be an endemic of the rio Aripuanã in the southern Amazon basin.

Keywords:
Brazilian Shield; Characiformes; Cyphocharax spilurus clade; Madeira River; Ostariophysi